A facile method to prepare uniform polypyrrole (PPy) nanospheres is developed by using 3-chloroperbenzoic acid as oxidant, structure-induced reagent and dopant for polymerization of pyrrole without introducing extra acid, template and surfactant. The as-synthesized PPy nanospheres with an average diameter of 100-200 nm and conductivity about 10(-2) S cm(-1) are characterized by SEM, FTIR, UV-vis spectroscopy, XRD and elemental analysis in an effort to determine the identity of the nanospheres and the mechanism relevant to their formation and stabilization. Influences of experimental conditions on the morphology of the PPy nanospheres have been investigated. Via the high temperature pyrolyzation at 900 degrees C, the nitrogen-doped carbon nanospheres have been obtained from the PPy nanospheres precursors, which have a high conductivity of 10-100 S cm(-1), showing a good potential as the electrode materials for high-performance supercapacitors due to their excellent electrochemical performance. (C) 2014 Elsevier Ltd. All rights reserved.